rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=deac/1/0x4000000000000000 softirq=53377/53378 fqs=2 rcu: (detected by 0, t=10506 jiffies, g=40521, q=379 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11525 Comm: syz.3.1309 Not tainted 6.15.0-rc2-syzkaller-00493-gac71fabf1567 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__kasan_check_write+0xa/0x20 mm/kasan/shadow.c:37 Code: ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 89 f6 48 8b 0c 24 01 00 00 00 e9 9c e6 ff ff 66 66 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc90000a08c08 EFLAGS: 00000082 RAX: ffffffff8a25edd9 RBX: ffff888021765800 RCX: ffffffff8a25edf3 RDX: 0000000000010000 RSI: 0000000000000004 RDI: ffff888021765880 RBP: 0000000000000000 R08: ffffffff8a25edca R09: 1ffff11004aa3a5c R10: dffffc0000000000 R11: ffffed1004aa3a5d R12: 0000000000000000 R13: ffff888021765800 R14: ffff888021765880 R15: 0000000000000000 FS: 00007f31d6acc6c0(0000) GS:ffff88812509a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c299007 CR3: 000000007eef8000 CR4: 0000000000350ef0 Call Trace: instrument_atomic_write include/linux/instrumented.h:82 [inline] atomic_set include/linux/atomic/atomic-instrumented.h:67 [inline] taprio_set_budgets+0x233/0x380 net/sched/sch_taprio.c:672 advance_sched+0x98d/0xca0 net/sched/sch_taprio.c:977 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x5a8/0xd40 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x112/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x0/0x90 kernel/kcov.c:320 Code: 10 48 89 74 0a 18 4c 89 44 0a 20 e9 25 7f 4d ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 4c 8b 04 24 65 48 8b 0c 25 08 60 68 93 65 8b 05 18 9e RSP: 0018:ffffc90013bfefa0 EFLAGS: 00000287 RAX: ffffffff8238ea22 RBX: 0000000000079f4e RCX: 0000000000080000 RDX: ffffc9000c462000 RSI: 0000000000079f4e RDI: 0010000000000000 RBP: ffffc90013bff0f0 R08: ffffffff8238da3c R09: 1ffffd40003cfa70 R10: dffffc0000000000 R11: fffff940003cfa71 R12: 0000000000000001 R13: 0000000000079f4e R14: 0000000079f4e027 R15: 1ffff9200277fe10 pfn_valid+0x24/0x450 include/linux/mmzone.h:2111 page_table_check_set+0x25/0x700 mm/page_table_check.c:105 __page_table_check_ptes_set+0x365/0x400 mm/page_table_check.c:209 page_table_check_ptes_set include/linux/page_table_check.h:74 [inline] set_ptes include/linux/pgtable.h:292 [inline] set_pte_range+0x728/0x750 mm/memory.c:5258 finish_fault+0xf89/0x12a0 mm/memory.c:5382 do_read_fault mm/memory.c:5522 [inline] do_fault mm/memory.c:5652 [inline] do_pte_missing mm/memory.c:4160 [inline] handle_pte_fault+0x3f3e/0x61c0 mm/memory.c:5997 __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1129/0x1bf0 mm/memory.c:6309 faultin_page mm/gup.c:1193 [inline] __get_user_pages+0x1adc/0x4180 mm/gup.c:1491 populate_vma_page_range+0x266/0x340 mm/gup.c:1929 __mm_populate+0x27d/0x460 mm/gup.c:2032 mm_populate include/linux/mm.h:3487 [inline] vm_mmap_pgoff+0x390/0x530 mm/util.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f31d5b8e169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f31d6acc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f31d5db5fa0 RCX: 00007f31d5b8e169 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f31d5c10a68 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f31d5db5fa0 R15: 00007ffc07ec46e8 rcu: rcu_preempt kthread starved for 10495 jiffies! g40521 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:25608 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b9/0x940 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted 6.15.0-rc2-syzkaller-00493-gac71fabf1567 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x1bb6/0x2d40 kernel/smp.c:885 Code: 89 e6 83 e6 01 31 ff e8 88 dd 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 38 d9 0b 00 eb 41 f3 90 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 03 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 13 d9 0b RSP: 0018:ffffc90000117640 EFLAGS: 00000293 RAX: dffffc0000000000 RBX: 1ffff110170e7e91 RCX: ffff88801c2fda00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000117840 R08: ffffffff81b6e3d8 R09: 1ffffffff20bfcae R10: dffffc0000000000 R11: fffffbfff20bfcaf R12: ffff8880b863ad08 R13: ffff8880b873f488 R14: ffff8880b863ad00 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888124f9a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1b6ece56c0 CR3: 000000000eb38000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2455 [inline] text_poke_bp_batch+0x354/0xb30 arch/x86/kernel/alternative.c:2665 text_poke_flush arch/x86/kernel/alternative.c:2856 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2863 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xc0/0x250 mm/kfence/core.c:850 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac5/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b9/0x940 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245